Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

315
FXUS63 KLOT 252308
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
608 PM CDT Mon May 25 2026

.KEY MESSAGES...

- Above normal temperatures (highs in the 80s) are expected much
  of this week with onshore winds keeping temperatures cooler
  near the Lake Michigan shore (60s and 70s).

- Other than a low (20%) chance of showers and storms Wednesday
  afternoon near the WI/IL state line as well as near/south of
  US-24, dry conditions are favored through the end of the week.

&&

.DISCUSSION...
Issued at 130 PM CDT Mon May 25 2026

A broad surface high continues to reside over the southern
Great Lakes and northern Ohio River Valley this afternoon. As a
result, sunny skies are being seen across the area with
temperatures to warm into the lower to mid-80s this afternoon.
While there is a shortwave disturbance pivoting across southern
WI and northern IL, the earlier rain showers associated with it
continue to weaken as the system encounters drier air. Though, a
period of partly to mostly cloudy skies is expected for our
northern tier of counties for a few hours this afternoon.

Heading into this evening, a weak lake breeze will ooze onshore
in northeast IL which will result in quickly cooling
temperatures towards the 60s there. Otherwise, expect mostly
clear conditions tonight aside from some high cirrus lifting
northward from the broad area of showers and thunderstorms along
the Gulf Coast. Overnight lows will bottom out in the upper 50s
and lower 60s. Tuesday will feature similar conditions to today
with highs once again in the mid-80s with slightly cooler
conditions (mid-70s) near the lake due to another lake breeze.
Though, increasing cloud cover is expected on Tuesday and
Tuesday night which will aid in keeping nighttime lows a couple
degrees warmer in the lower to mid-60s.

While we enjoy the tranquil weather on Tuesday, a broad upper
trough will begin to dig into the northeast CONUS. At the same
time, the upper low off the Pacific Northwest will also begin to
dig into the southwest CONUS which in turn will begin to eject
the weak shortwave causing the showers/storms near the Gulf
northward towards IL and IN on Wednesday. Given that most of
northern IL and northwest IN will still be under the influence
of an elongated ridge, it seems that the bulk of the
aforementioned showers and storms lifting towards the area
should stay more into central IL and IN. Therefore, another
mostly dry day is expected for Wednesday but an isolated shower
or storm (20% chance) cannot be ruled out near and south of
US-24. Furthermore, there will also be a cold front diving
southward out of WI Wednesday afternoon and evening which could
also bring a few showers/storms to portions of northern IL.
However, with forecast soundings looking somewhat dry and the
better forcing with the upper trough forecast to be more into
MI, it seems the coverage of any showers/storms with the front
will be very hit and miss especially with southward extent. So
while the official forecast does have some 20-30% POPs near the
IL-WI line there is a chance that most of these areas remain
dry.

Regardless, temperatures will quickly cool behind the front as
north-northeast winds usher in cooler air. With the front`s
later arrival (current forecast is for fropa to occur late
afternoon) highs on Wednesday should still get into the lower to
mid-80s (upper 60 near the lake), but if the front arrives
quicker than expected temperatures could verify much cooler. In
addition to the cooling temperatures, winds behind the front
also look to become breezy with gusts around 20-25 mph. These
north-northeast winds will allow waves to build on Lake
Michigan and result in rip currents and dangerous swimming
conditions at IL and northwest IN beaches.

High pressure is expected to build back into the Great Lakes
Wednesday night through weeks end which will result in dry and
tranquil weather conditions. Though, persistent northeast winds
do look to keep temperatures more in the seasonable range with
daily highs in the upper 70s to lower 80s (60s near the lake),
especially on Thursday, and overnight lows in the 50s through
next weekend.

Yack

&&

.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 608 PM CDT Mon May 25 2026

There are no significant aviation weather concerns through the
period. Winds will trend light S/SE this evening before
returning out of the SW late tonight into Tuesday morning. A
lake breeze will turn winds SE at ORD, MDW, and GYY Tuesday
afternoon. Otherwise, VFR conditions with an increase in cirrus
cloud cover will prevail.

Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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